Ron and Diane......love the potato chip bag story.
NancyA........like Wilcut said, we have the tow haul on any time we are moving. Make sure you have propane off and any appliances (flame) off before you enter any tunnels.
As you start the decent, establish your speed at least 5 miles slower than the posted speed, stay off the throttle and let the "engine brake" in the tow haul and engine/transmission do their work. If you find you are going to fast down, apply your brake firmly long enough for the computer to realize you want the next gear lower. It will shift, remove your foot from the brake.
We are in southern CO now at 8100 elevation and loving it.
Enjoy,
Darrell & Mary